At least 24 people were killed and 35 injured on Monday, when a bus careened off the edge of a rural mountain road in southeastern Peru, according to police and health officials.

The accident occurred before dawn, when a bus travelling between two Andean towns overturned and fell into a 200-metre-deep ravine in the region of Huancavelica, a police official said.

"The number of dead has risen to 24, including two children," the health ministry posted on social media. The police had earlier reported 20 deaths.

An accident in the same region last month left 13 people dead and five seriously wounded.

Accidents frequently occur along Peruvian highways due to speeding, poor road conditions, lack of signage and poor enforcement of traffic rules.

The World Health Organisation estimated 4,414 road fatalities in Peru in 2019, or 13.6 per 100,000 inhabitants. (AFP)